Abstract:

Recording heads for a data storage system include a first diode, a second
diode, and a first electrical component. The first electrical component
is electrically connected in series to the first and second diodes. In
another embodiment, recording heads include first, second, third, and
fourth electrical connection points. A read transducer is electrically
connected to the first and second electrical connection points. A write
transducer is electrically connected to the first and third electrical
connection points. A first heater and a second heater are electrically
connected to the first and fourth electrical connection points.

Claims:

1. A recording head comprising:a first diode;a second diode; anda first
electrical component that is electrically connected in series to the
first and second diodes.

2. The recording head of claim 1 wherein the first diode and the second
diode are on opposite sides of the first electrical component.

3. The recording head of claim 2 wherein the first electrical component is
a heater.

4. The recording head of claim 3 wherein the heater is positioned
proximate a write transducer.

5. The recording head of claim 4 wherein the heater is positioned
proximate a read transducer.

6. The recording head of claim 1 further comprising:a third diode;a fourth
diode; anda second electrical component that is electrically connected to
the third and the fourth diodes.

7. The recording head of claim 6 wherein the first and the second
electrical components are electrically connected in parallel.

8. The recording head of claim 7 wherein the first and second diodes are
biased in a first direction, and wherein the third and fourth diodes are
biased in a second direction.

9. A data storage system comprising:a recording head having a first
electrical connection point, a second electrical connection point, a
first electrical path having a first diode, and a second electrical path
having a second diode, the first and second electrical connection points
electrically connected through the first and second electrical paths, the
first and second paths being electrically parallel; anda power supply
component having a first terminal and a second terminal, the first
terminal electrically connected to the first electrical connection point,
the second terminal electrically connected to the second electrical
connection point.

10. The data storage system of claim 9 wherein the first terminal has a
first voltage, wherein the second terminal has a second voltage, and
wherein the first and second voltages have the same magnitude and
opposite polarities.

11. The data storage system of claim 9 wherein the first terminal has a
first voltage, wherein the second terminal has a second voltage, and
wherein the first and second voltages have different magnitudes and the
same polarity.

12. The data storage system of claim 11 wherein the same polarity is
positive.

13. The data storage system of claim 11 where the same polarity is
negative.

14. The data storage system of claim 9 wherein the first terminal has a
first voltage, wherein the second terminal has a second voltage, and
wherein the first and second voltages have different magnitudes and
opposite polarities.

15. The data storage system of claim 9 wherein the first electrical path
has a third diode.

16. A recording head comprising:a first electrical connection point;a
second electrical connection point;a third electrical connection point;a
fourth electrical connection point;a read transducer electrically
connected to the first and second electrical connection points;a write
transducer electrically connected to the first and third electrical
connection points;a first heater electrically connected to the first and
fourth electrical connection points; anda second heater electrically
connected to the first and fourth electrical connection points.

17. The recording head of claim 16 wherein the first heater and the second
heater are electrically parallel.

18. The recording head of claim 17 further comprising:a first diode
connected in series to the first heater; anda second diode connected in
series to the second heater.

19. The recording head of claim 18 wherein the first diode has a first
bias, and wherein the second diode has a second bias.

20. The recording head of claim 19 further comprising:a third diode
connected in series to the first heater and the first diode; anda fourth
diode connected in series to the second heater and the second diode.

Description:

BACKGROUND

[0001]Data storage systems commonly have a recording head that reads
information from a recording medium and that writes information to a
recording medium. Recording heads may also have other electrical
components such as a heater. Recording head heaters may be used to
actuate another recording head component such as a read transducer or a
write transducer.

[0002]Recording heads do not have internal power supplies to enable their
electrical components to function. Instead, they rely on external power
sources that are electrically connected to electrical connection points
located on or within the bodies of the recording heads.

SUMMARY

[0003]An aspect of the disclosure relates to recording head heater systems
that operate using two electrical connection points. In one embodiment,
recording heads include a first diode, a second diode, and a first
electrical component. The first electrical component is illustratively a
heater and is electrically connected in series to the first and second
diodes.

[0004]In another embodiment, data storage systems include a recording head
and a power supply component. The recording head has a two electrical
connection points. Two electrical paths are connected in parallel between
the two electrical connection points. Each of the paths has a diode. The
power supply component has two terminals. One of the terminals is
connected to one of the recording head electrical connection points, and
the other terminal is connected to the other recording head electrical
connection point.

[0005]In yet another embodiment, recording heads include first, second,
third, and fourth electrical connection points. A read transducer is
electrically connected to the first and second electrical connection
points. A write transducer is electrically connected to the first and
third electrical connection points. A first heater and a second heater
are electrically connected to the first and fourth electrical connection
points.

[0006]These and various other features and advantages that characterize
the claimed embodiments will become apparent upon reading the following
detailed description and upon reviewing the associated drawings.

BRIEF DESCRIPTIONS OF THE DRAWINGS

[0007]FIG. 1 is a perspective view of a data storage system.

[0008]FIG. 2 is a generalized functional block diagram of a data storage
system.

[0009]FIG. 3 is a schematic diagram of a cross-section of a recording head
writing to a storage medium.

[0010]FIG. 4 is a schematic diagram of a recording head having a first and
a second heater.

[0011]FIG. 5 is a schematic diagram of a four diode recording head dual
heater system.

[0012]FIG. 6 is a schematic diagram of a two diode recording head dual
heater system.

[0013]FIG. 7A is a schematic diagram of a four diode dual heater system
with an unbalanced power supply.

[0014]FIG. 7B is a schematic diagram of a two diode dual heater system
with an unbalanced power supply.

[0015]FIG. 8 is a schematic diagram of a recording head that operates four
electrical components using four electrical connection points.

DETAILED DESCRIPTION

[0016]In one embodiment of the present disclosure, recording heads have
dual heaters that receive power from an external source through two
electrical connection points. Previous recording heads have commonly used
three electrical connection points to receive power for dual heaters. Due
to the limited space on recording heads for electrical connection points,
it is desirable to have as few of them as possible. Additionally, certain
embodiments of the present disclosure include methods and devices that
operate recording head heaters with improved electrical characteristics.
For example, in one embodiment, heaters are operated such that the
voltage across each heater is the same or more similar to the voltage of
other recording head components such as a write transducer or a read
transducer. Also for example, in an embodiment, the centers of the
heaters are at or approximately at zero volts when they are operated.
These illustrative electrical characteristics are advantageous for many
reasons. For instance, if a heater is separated from a write transducer
by a dielectric layer, and the heater is at a higher voltage than the
write transducer, this voltage difference across the dielectric layer may
cause an electrical break down of the dielectric layer. Also for
instance, a read transducer may be adversely affected by a heater. If a
heater generates too large of a voltage near the read transducer, the
operation of the transducer may be interfered with or the materials in
the transducer may be damaged.

[0017]FIGS. 1, 2, 3, and 4 are illustrative operating environments in
which certain embodiments disclosed herein may be incorporated. The
operating environments shown in the figures are for illustration purposes
only. Embodiments of the present disclosure are not limited to any
particular operating environment such as those shown in FIGS. 1, 2, 3,
and 4. Embodiments of the present disclosure are illustratively practiced
within any number of different types of operating environments.

[0018]FIG. 1 is a perspective view of a hard disc drive 100. Hard disc
drives are a common type of data storage system. While embodiments of
this disclosure are described in terms of disc drives, other types of
data storage systems should be considered within the scope of the present
disclosure.

[0019]Disc drive 100 includes a magnetic disc or recording medium 110.
Those skilled in the art will recognize that disc drive 100 can contain a
single disc or multiple discs. Medium 110 is mounted on a spindle motor
assembly 115 that facilitates rotation of the medium about a central
axis. An illustrative direction of rotation is shown by arrow 117. Each
disc surface has an associated recording head 120 that carries a read
transducer and a write transducer for communication with the surface of
the disc. Each head 120 is supported by a head gimbal assembly 125. Each
head gimbal assembly (HGA) 125 illustratively includes a suspension and a
HGA circuit. Each HGA circuit provides electrical pathways between a
recording head and associated hard disc drive electrical components
including preamplifiers, controllers, printed circuit boards, or other
components. Each suspension mechanically supports an HGA circuit and a
recording head 120, and transfers motion from actuator arm 130 to
recording head 120. Each actuator arm 130 is rotated about a shaft by a
voice coil motor assembly 140. As voice coil motor assembly 140 rotates
actuator arm 130, head 120 moves in an arcuate path between a disc inner
diameter 145 and a disc outer diameter 150.

[0020]FIG. 2 is a generalized block diagram of illustrative control
circuitry for the device shown in FIG. 1. The control circuitry includes
a processor or controller 202 that directs or manages the high level
operations of device 100. An interface circuit 204 facilitates
communication between device 100 and a host device 250. A read/write
channel 206 operates in conjunction with a preamplifier/driver circuit
(preamp) 208 to write data to and to read data from a recording medium
such medium 110 in FIG. 1. Preamp 208 also optionally acts as a power
supply to electrical components included in a recording head such as a
read transducer, a write transducer, heaters, etc. Preamp 208 is
illustratively electrically connected to recording head 120 through an
HGA circuit that is connected to preamp 208 and to one or more recording
head 120 electrical connection points. A servo circuit 210 provides
closed loop positional control for voice coil motor 140 that positions
recording head 120.

[0021]FIG. 3 is a schematic diagram showing a cross-sectional view of
portions of a recording head 300 and a recording medium 350. The
recording head elements shown in FIG. 3 are illustratively included in a
recording head such as recording head 120 in FIGS. 1 and 2. Medium 350 is
illustratively a recording medium such as medium 110 in FIG. 1. Those
skilled in the art will recognize that recording heads and recording
media commonly include other components. Embodiments of the present
disclosure are not limited to any particular recording heads or media.
Embodiments of the present disclosure are practiced in all types of
recording heads and media.

[0022]Recording head 300 includes a write pole 305, a magnetization coil
310, a return pole 315, a read transducer 320, and a bottom shield 325.
Storage medium 350 includes a recording layer 355 and an underlayer 360.
Storage medium 350 rotates in the direction shown by arrow 365. Arrow 365
is illustratively a direction of rotation such as arrow 117 in FIG. 1.

[0023]In an embodiment, electric current is passed through coil 310 to
generate a magnetic field. The magnetic field passes from write pole 305,
through recording layer 355, into underlayer 360, and across to return
pole 315. The magnetic field illustratively records a magnetization
pattern 370 in recording layer 355. Read transducer 320 senses or detects
magnetization patterns in recording layer 355, and is used in retrieving
information previously recorded to layer 355.

[0024]FIG. 3 includes a spacing 375 that represents the spacing or
distance between write pole 305 and the surface of storage medium 350.
Spacing 375 is one factor that determines the strength of a magnetic
field on the storage medium. As spacing 375 increases, the strength of
the magnetic field decreases. If spacing 275 is too great, the magnetic
field may be too weak to write efficiently.

[0025]FIG. 3 also includes a spacing 385 that represents the spacing or
distance between read transducer 320 and the surface of storage medium
350. Spacing 385 is one factor that determines the ability of transducer
320 to detect magnetization patterns recorded to medium 350. Transducer
320 is illustratively better able to detect magnetization patterns as
spacing 385 decreases.

[0026]FIG. 4 is a top down schematic diagram of a portion of a dual heater
recording head 400. Head 400 includes a magnetization coil 410 that is
illustratively a magnetization coil such as coil 310 in FIG. 3, and a
write pole 405 that is illustratively a write pole such as pole 305 in
FIG. 3. Head 400 also includes a first heater 425 and a second heater
435. Heaters 425 and 435 are illustratively electrically resistive
heaters that generate thermal energy as an electric current passes
through them. As can be seen in the figure, heater 425 is positioned or
located proximate to write pole 405. Accordingly, as current passes
through heater 425, it generates thermal energy that is transferred to
the write transducer. This causes the write transducer to thermally
expand which in return reduces the spacing between the write transducer
and a recording medium (e.g. it decreases spacing 375 in FIG. 3).

[0027]Second heater 435 is positioned or located away from write pole 405.
In an embodiment, heater 435 is positioned or located proximate to a read
transducer such that thermal energy from heater 435 is transferred to the
read transducer. This causes the read transducer or an area that includes
the read transducer to thermally expand, which in turn decreases the
spacing between the read transducer and a recording medium (e.g. it
decreases spacing 385 in FIG. 3).

[0028]As was previously mentioned, FIGS. 1, 2, 3, and 4 are only
illustrative operating environments in which some embodiments of the
present disclosure may be incorporated. Embodiments are not limited to
the specific recording heads, read transducers, write transducers,
storage devices, control circuitry, or heaters shown in the figures.
Embodiments are incorporated in environments that include any recording
head, read transducer, write transducer, storage device, control
circuitry, or heater.

[0029]FIG. 5 is schematic diagram of one embodiment of a recording head
heater system according to the present disclosure. FIG. 5 includes a
recording head 500 electrically connected to a balanced power supply
component 550 through a first electrical trace 561 and a second
electrical trace 562. Power supply component 550 is illustratively a
preamp or other electrical component in a data storage system, and traces
561 and 562 are illustratively included in an HGA circuit. It should be
noted that recording head 500 is shown to only include components
associated with a heater system. Embodiments of head 500 include other
components such as, but not limited to, read transducers, write
transducers, air bearing surfaces, and additional electrical connection
points. Head 500 is presented in simplified form to highlight features of
the heater system.

[0030]Head 500 includes a first heater 510 and a second heater 520.
Heaters 510 and 520 are illustratively resistive heating elements that
generate thermal energy as a current passes through them. In an
embodiment, heaters 510 and 520 are positioned or formed such that they
transfer thermal energy to different portions or features of head 500.
For example, in one embodiment, heater 510 is configured such that it
transfers thermal energy to a write transducer, and heater 520 is
configured such that it transfers thermal energy to a read transducer.
Embodiments of the present disclosure are not however limited to any
particular configurations of heaters.

[0031]First heater 510 and second heater 520 share two electrical
connection points that are within head 500, a first electrical connection
point 531 and a second electrical connection point 532. Heater 510 is on
a first electrical path or leg between points 531 and 532 (i.e. the path
between points 531 and 532 that passes through heater 510), and heater
520 is on a second electrical path or leg between points 531 and 532
(i.e. the path between points 531 and 532 that passes through heater
520). As is shown in the figure, the first and second paths or legs are
illustratively electrically parallel.

[0032]Each path between points 531 and 532 includes two diodes that are
electrically connected in series to the heaters. Heater 510 has a first
diode 511 on one side and a second diode 512 on its other side. Heater
520 has a first diode 521 on one side and a second diode 522 on its other
side. Each diode has a unidirectional electric property. The diodes allow
a current to flow in one direction (i.e. the forward biased condition)
and block current flow in the opposite direction (i.e. the reverse biased
condition). The two diodes in each path are illustratively biased in the
same direction (e.g. diodes 511 and 512 have the same bias, and diodes
521 and 522 have the same bias), and the diodes in the two paths are
illustratively biased in opposite directions (e.g. diodes 511 and 512 are
biased in the opposite direction from diodes 521 and 522).

[0033]Each diode has an associated "cut in" voltage and voltage drop
across the diode. For example, for a diode having a "cut in" voltage of
0.6 volts, a voltage of 0.6 volts or greater (in the correct polarity) is
needed for current to flow through the diode, and the diode will have a
voltage drop across the diode of 0.6 volts. In one embodiment, diodes
511, 512, 521, and 522 have the same or approximately the same
characteristics (e.g. the same "cut in" voltages). In another embodiment
the diodes in each path have the same characteristics, but have different
characteristics from the diodes in the other path (e.g. diodes 511 and
512 have the same "cut in" voltage, and diodes 521 and 522 have the same
"cut in" voltage which is different than that of diodes 511 and 512).
Embodiments of diodes are not however limited to any particular diode
characteristics, types of diodes, or configurations of diodes.
Embodiments include diodes of any type, with any characteristics, and
with any configuration.

[0034]Electrical connection point 531 is electrically connected within the
recording head to a first recording head external connection point 541,
and electrical connection point 532 is electrically connected within the
recording head to a second recording head external connection point 542.
Points 541 and 542 are illustratively on or within the recording head,
and are configured such that they facilitate or enable an external device
such as, but not limited to, an HGA circuit and/or a preamp to
electrically connect to the recording head. In an embodiment, points 541
and 542 are bond pads that have surfaces that enable an HGA circuit to be
soldered to or otherwise attached to the recording head. Embodiments of
points 541 and 542 are not however limited to any particular
configuration.

[0035]Power supply component 550 includes a first terminal 551, a second
terminal 552, and a ground reference 553. Component 550 is illustratively
a balanced power supply component in that the voltages on terminals 551
and 552 have the same magnitude, but opposite polarities. Component 550
is illustratively able to generate any magnitude of voltages and is able
to switch the polarities of the terminals. For example, for illustration
purposes only and not by limitation, supply 550 is able to switch between
terminal 551 having a voltage of +1.1 volts and terminal 552 having a
voltage of -1.1 volts, and terminal 551 having a voltage of -1.1 volts
and terminal 552 having a voltage of +1.1 volts.

[0036]The heater system of FIG. 5 has several different operational modes.
In one mode, no voltage is supplied at either terminal 551 or 552. In
this case, no electrical current flows through either heater 510 or
heater 520. This mode can be useful in many settings. For example, the
spacing between a recording head transducer and a recording medium
generally decreases with reduced pressure (e.g. at higher elevations). In
such a situation, it may not be necessary to thermally expand any of the
components of a recording head. Also for example, it may be useful to
intermittently turn the heaters on and off to establish a steady state or
approximately steady state amount of thermal expansion/heating (i.e. as
opposed to continuously leaving the heaters on).

[0037]In a second mode, terminal 551 has a positive voltage, and terminal
552 has a voltage of the same magnitude as that of terminal 551 but of
the opposite polarity (i.e. it has a negative voltage). In an embodiment
where the heaters have oppositely biased diodes, the diodes of one of the
heaters will be in the forward biased condition. In this case, if the
voltage differential between terminals 551 and 552 is equal to or greater
than the combined "cut in" voltages for both of the diodes (e.g. diodes
511 and 512), then current will flow through the heater. For example, if
terminal 551 has a voltage of +1.1 volts and terminal 552 has a voltage
of -1.1 volts, then the voltage differential between the terminals is 2.2
volts. If diodes 511 and 512 are forward biased and the "cut in" voltages
for both are 0.6 volts, then the voltage differential of 2.2 volts is
greater than the "cut in" voltages of both diodes (i.e. 0.6+0.6=1.2
volts). The result is that current will flow through heater 510 and there
will be a voltage drop of 1.0 volts across the heater.

[0038]It is worth highlighting a few points about this mode. First,
because of the symmetrical or balanced nature of the circuit (i.e.
terminals 551 and 552 have the same magnitude of voltage but opposite
polarities, and diodes 511 and 512 have the same "cut in" voltage), the
point along the circuit that has a ground potential or a voltage of zero
volts is in the middle of the heater. Similarly, the ends of the heater
(i.e. the parts of the heater closest to diodes 511 and 512) have the
same magnitude or approximately same magnitude of voltage but of opposite
polarity (e.g. in the example given above, one end of the heater has a
voltage of -0.5 volts and the other end has a voltage of +0.5 volts).
Additionally, because the voltages at terminals 551 and 552 can be set to
provide any voltage differential, the voltage drop across the heater can
be set to be any value (e.g. it was set to 1.0 volts in the example
above).

[0039]These electrical characteristics are advantageous in recording
heads. For instance, as was previously mentioned, large voltage
differences between electrical components in a recording head can cause
dielectric breakdown. Also as was previously mentioned, heaters at a high
voltage can interfere or damage other electrical components. In the
system of FIG. 5, the center of the heater is at ground potential and is
thus not at a high voltage. Additionally, the voltage drop across the
heater can be set to any value. Accordingly, it is illustratively set to
be the same or approximately the same as other components in a recording
head. This reduces or eliminates voltage differentials across a
dielectric layer caused by a heater.

[0040]In a third mode of operation of the system of FIG. 5, terminal 551
has a negative voltage, and terminal 552 has a voltage of the same
magnitude as that of terminal 551 but of the opposite polarity (i.e. it
has a positive voltage). This mode is essentially the opposite of the
previously described mode. The polarity of the voltage differential
across the recording head circuit is the opposite of what it was in the
second mode. In this case, the diodes of the heater that were in the
forward biased condition in the second mode are now in the reverse biased
condition. Accordingly, current will not flow through the heater that
received current in the second mode, and the heater will be off (i.e. it
will not generate thermal energy). However, the diodes that were
previously in the reverse biased condition are now in the forward bias
condition. Consequently, current may now flow through the other heater.
For example, if diodes 521 and 522 are in the forward biased condition
and the voltage differential between terminals 551 and 552 is greater
than the combined "cut in" voltages of diodes 521 and 522, then current
will flow through the second heater 520. In one embodiment, diodes 521
and 522 have the same "cut in" voltage values. Accordingly, the balanced
or symmetrical electrical properties previously discussed in discussing
the second mode, also apply to this mode. The difference between the
second and third modes is that the heater that was turned on in the
second mode is now turned off, and the heater that was turned off in the
second mode is now turned on.

[0041]In an embodiment, the voltage differentials used to power the first
and second heaters are the same. In another embodiment, the voltage
differentials used to power the first and second heaters are different.
Similarly, the resistances of the heaters are also illustratively either
the same or different. The voltage differentials and resistances are
optionally chosen to optimize performance of a recording head. For
example, a recording head may require two heaters that provide different
amounts of thermal energy or that have different voltage drops across the
heaters. The voltages and resistance are chosen such that the correct
combination of thermal energy and/or voltage drop is provided.

[0042]So far, the system of FIG. 5 has only been described in the context
of using equal magnitude voltages with opposite polarities to power
recording head 500. The recording head 500 circuitry is also
illustratively used with any configuration of a power supply component.
For example, the circuitry is illustratively used with an unbalanced
power supply component (i.e. a component that provides any two different
voltages on terminals 551 and 552), a floating power supply (i.e. a
component that provides any voltage differential across terminals 551 and
552 without an explicit reference to ground), or an alternating current
power supply. Embodiments of recording head 500 are not limited to any
particular power supply component or configuration.

[0043]Additionally, the system of FIG. 5 has only been discussed in the
context of a recording head having two heaters 510 and 520. In an
embodiment, recording head 500 only includes one heater. In such a case,
the advantageous electrical properties associated with the two heater
system (e.g. having a voltage of zero volts at a center of a heater) are
also realized in a one heater system. In another embodiment, heaters 510
and 520 are illustratively replaced with any electrical component such as
a read transducer or a write transducer. The system of FIG. 5 is not
limited to only being used with heaters.

[0044]FIG. 6 is a schematic diagram of another embodiment of a recording
head heater system. The system in FIG. 6 has many of the same or similar
components as the system in FIG. 5, and the FIG. 6 components are
numbered accordingly. The main points that will be discussed in reference
to FIG. 6 are the differences between it and FIG. 5. In one embodiment,
the system of FIG. 6 has an unbalanced power supply 650. Each of the
voltages at terminals 651 and 652 has a ground reference (i.e. ground
references 653 and 654), and the voltages at the terminals include any
values that provide a voltage differential (i.e. the voltages at
terminals 651 and 652 are any two unequal voltages). Recording head 600
has two diodes 611 and 621 on electrically parallel paths that also
include heaters 610 and 620. Diode 611 is illustratively electrically
connected in series to heater 610, and diode 621 is illustratively
electrically connected in series to heater 620. The polarity of the
voltage differential applied to electrical connection points 641 and 642
is reversed to alternate between which one of the two heaters receives
current.

[0045]The voltages at terminals 651 and 652 are illustratively chosen such
that the centers of the heaters are at zero or ground potential when the
heaters are being operated. For example, in one embodiment, terminal 651
has a voltage of +1.1 volts that is applied to electrical connection
point 641, and terminal 652 has a voltage of -0.5 volts that is applied
to electrical connection point 642. This creates a voltage differential
of 1.6 volts across the recording head heater circuit. In an embodiment,
diode 611 is oriented such that it is forward biased with this voltage
differential and diode 621 is oriented such that it is reversed biased
with the voltage differential. Diodes 611 and 621 optionally include any
"cut in" voltage. For illustration purposes only and not by limitation,
diodes 611 and 612 have "cut in" voltages of 0.6 volts. Accordingly,
current flows through heater 610 and no current flows through heater 620.
The voltage drop across diode 611 is 0.6 volts and the voltage drop
across heater 610 is 1.0 volts.

[0046]It is worth noting that in the example given above, that the
voltages at the ends of heater 610 are +0.5 volts and -0.5 volts, and
that the voltage at the center of the heater is 0 volts, or in other
words, at ground potential. These heater voltages and the voltage drop
across the heater are the same as the values for the example discussed in
connection with the FIG. 5 system. Consequently, the same or similar
benefits of having reduced voltages at a heater and reduced voltage
differentials between the heaters and other electrical components may be
realized for the system of FIG. 5.

[0047]Similar to the system of FIG. 5, in the system of FIG. 6, the
voltages, voltage differentials, resistances of the heaters, number of
heaters, and the "cut in" voltages of the diodes can include any values.
The values are illustratively chosen such that the heaters produce an
adequate amount of thermal energy and that the heaters have the same or
similar voltages as other electrical components in the recording head.
The heaters of FIG. 5 are also illustratively replaced by one or more
electrical components other than a heater. Also, the system of FIG. 6 has
been described in the context of having an unbalanced power supply
component with ground references, the system of FIG. 6 optionally
includes any type of power supply component that is connected to
recording head 600 (e.g. balanced power supply, floating power supply,
alternating current, etc.).

[0048]FIGS. 7A and 7B illustrate systems in which recording head 500 in
FIG. 5 and recording head 600 in FIG. 6 are powered using a floating
power supply 750. Power supply 750 does not have a reference to ground
such as reference 553 in FIG. 5 or references 653 and 654 in FIG. 6.
Power supply 750 is illustratively able to generate any voltage
differential across terminals 751 and 752 (e.g. +2.2 volts, -2.2 volts,
+1.6 volts, -1.6 volts, etc.). Accordingly, power supply 750 is able to
control the heater systems such that one heater in the system is
selectively turned on and the other is turned off. However, the value of
the voltages at terminals 751 and 752 are not known. Consequently,
although the voltage drops across the recording head circuit components
are known, the values of the voltages at points in the circuit are not
known.

[0049]The systems shown in FIGS. 7A and 7B provide several advantages. For
example, other electrical components in the recording head may be
similarly powered by a floating power supply. In such a case, the use of
a floating power supply allows for the voltages across the heater systems
to be the same or similar to voltages of other recording head components.
This reduces voltage differentials between the heaters and other
components. The systems in FIGS. 7A and 7B may also be advantageous based
on power supply availability and costs.

[0050]FIG. 8 is a schematic diagram of a recording head 800 that operates
four electrical components using four recording head electrical
connection points, 801, 802, 803, and 804. In an embodiment, the first
electrical component 810 is a recording head read transducer, the second
electrical component 820 is a recording head write transducer, the third
electrical component 830 is a first heater, and the fourth electrical
component 840 is a second heater. The four electrical components are each
connected to electrical connection point 801. First electrical component
810 is also connected to point 802. Second electrical component 820 is
also connected to point 803, and the third electrical component 830 and
the fourth electrical component 840 are each also connected to point 804.
As is shown in the figure, components 830 and 840 are illustratively
electrically parallel. Component 830 is illustratively electrically
connected in series to a diode 831, and component 840 is illustratively
connected in series to a diode 841. Diodes 831 and 841 are optionally
oriented such that they have opposite biases than each other. In an
embodiment, components 830 and 840 each has a second diode electrically
connected in series such as is shown in FIGS. 5 and 7A (i.e. each
component 830 and 840 has two associated diodes).

[0051]The electrical components are powered or operated by applying a
voltage differential across their associated connection points. For
example, current is flown through component 810 by applying a first
voltage to point 801 (which may be 0 volts) and a second voltage to point
802 that is different than the first voltage. Current is flown through
component 820 by applying a first voltage to point 801 and a second,
different voltage to point 803. For components 830 and 840, applying a
voltage differential across points 801 and 804 either flows a current
through component 830 or component 840. The component that receives a
current depends on the polarity of the voltage differential. The
component that receives current is switched by reversing the polarity.

[0052]Recording head 800 is optionally operated using any type of power
supply (e.g. balanced, unbalanced, floating, alternating current, etc.).
In one embodiment, for illustration purposes only and not by limitation,
the shared electrical connection point 801 is at ground (e.g. floating
ground or fixed ground) and voltages are applied to points 802, 803, and
804 to flow current to the components. The polarity of the voltage
applied to point 804 is reversed to switch between which of the two
electrically parallel components is being operated. In an embodiment, the
applied voltages are selected such that the voltage drops across the
electrical components are the same or approximately the same.

[0053]As can be seen in FIGS. 5, 6, 7A, 7B, and 8, certain embodiments of
the present disclosure operate multiple electrical components using a
reduced number of recording head electrical connection points.
Additionally, certain embodiments are configured such that electrical
voltages across recording heads are more balanced, which may reduce
harmful effects associated with voltage differentials between electrical
components of a recording head (e.g. dielectric breakdown). Additionally,
certain embodiments are configured such that they are able to operate
using multiple different types of power supplies, which may provide
design flexibility and reduce costs.

[0054]Finally, it is to be understood that even though numerous
characteristics and advantages of various embodiments have been set forth
in the foregoing description, together with details of the structure and
function of various embodiments, this detailed description is
illustrative only, and changes may be made in detail, especially in
matters of structure and arrangements of parts within the principles of
the present disclosure to the full extent indicated by the broad general
meaning of the terms in which the appended claims are expressed. In
addition, although the embodiments described herein are directed to hard
disc drives, it will be appreciated by those skilled in the art that the
teachings of the disclosure can be applied to other types of data storage
systems, without departing from the scope and spirit of the disclosure.